Recently, a technique for predicting a safe route to avoid a collision between moving bodies has been required in various fields such as a driving support system of a vehicle and air-traffic control.
For example, as for a driving support system of a vehicle, a technique has been developed which prevents a collision by acquiring the position of an obstacle such as a vehicle and stationary object existed in the periphery of a self vehicle with sensors like a millimeter wave radar or laser radar mounted on the self vehicle, by deciding a collision risk based on the relative distance and relative speed between the self vehicle and the obstacle, and then by controlling the self vehicle. In addition, as a higher technique, an automatic driving technique is being developed which recognizes a surrounding environment with sensors, carries out operations such as steering and braking automatically without the operation of a driver, and reaches a destination.
As a conventional technique relating to such a route prediction, a device disclosed in a Patent Document 1, for example, generates a plurality of prediction tracks of a vehicle in advance, and calculates existence probabilities of prediction routes in the time and space from the prediction tracks generated. In addition, a driving support device disclosed in a Patent Document 2, for example, calculates a risk potential map of a self vehicle with respect to other vehicles, and enables the control of the accelerator, brakes and the like based on the risk.
On the other hand, as for the air-traffic control, it has been considered to adopt a four-dimensional trajectory (4DT) including three-dimensional position and time into navigation in place of conventional navigation based on the three-dimensional position. The 4DT corresponds to a prediction route, and improvement in flight safety is expected because the management of the 4DT makes it possible to estimate an air traffic amount and airspace capacity. As a technique of such a route prediction, for example, a Patent Document 3 calculates future positions from the present speed and heading of a target on the assumption of linear uniform velocity.
In addition, a system disclosed in a Patent Document 4, for example, employs an optimum route search method based on an A* algorithm as a prediction method of the future positions. The algorithm determines nodes from a start to a goal (or via point) in a moving space in which a route candidate is divided into a mesh including a no entry area (obstacle).